/****************************************************************
 *																*		
 * 						      代码库							*
 *                        www.dmaku.com							*
 *       		  努力创建完善、持续更新插件以及模板			*
 * 																*
****************************************************************/
;(function(window) {

var ctx,
	hue,
	logo,
	form,
	buffer,
	target = {},
	tendrils = [],
	settings = {};

settings.debug = true;
settings.friction = 0.5;
settings.trails = 20;
settings.size = 50;
settings.dampening = 0.25;
settings.tension = 0.98;

Math.TWO_PI = Math.PI * 2;

// ========================================================================================
// Oscillator
// ----------------------------------------------------------------------------------------

function Oscillator(options) {
	this.init(options || {});
}

Oscillator.prototype = (function() {
	
	var value = 0;
	
	return {
		
		init: function(options) {
			this.phase = options.phase || 0;
			this.offset = options.offset || 0;
			this.frequency = options.frequency || 0.001;
			this.amplitude = options.amplitude || 1;
		},
		
		update: function() {
			this.phase += this.frequency;
			value = this.offset + Math.sin(this.phase) * this.amplitude;
			return value;
		},
		
		value: function() {
			return value;
		}
	};
		
})();

// ========================================================================================
// Tendril
// ----------------------------------------------------------------------------------------

function Tendril(options) {
	this.init(options || {});
}

Tendril.prototype = (function() {
	
	function Node() {
		this.x = 0;
		this.y = 0;
		this.vy = 0;
		this.vx = 0;
	}
	
	return {
	
		init: function(options) {
			
			this.spring = options.spring + (Math.random() * 0.1) - 0.05; 
			this.friction = settings.friction + (Math.random() * 0.01) - 0.005;
			this.nodes = [];
			
			for(var i = 0, node; i < settings.size; i++) {
		
				node = new Node();
				node.x = target.x;
				node.y = target.y;
		
				this.nodes.push(node);
			}	
		},
		
		update: function() {
			
			var spring = this.spring,
				node = this.nodes[0];
			
			node.vx += (target.x - node.x) * spring;
			node.vy += (target.y - node.y) * spring;
			
			for(var prev, i = 0, n = this.nodes.length; i < n; i++) {

				node = this.nodes[i];
				
				if(i > 0) {
					
					prev = this.nodes[i - 1];
					
					node.vx += (prev.x - node.x) * spring;
					node.vy += (prev.y - node.y) * spring;
					node.vx += prev.vx * settings.dampening;
					node.vy += prev.vy * settings.dampening;
				}
				
				node.vx *= this.friction;
				node.vy *= this.friction;
				node.x += node.vx;
				node.y += node.vy;
				
				spring *= settings.tension;
			}
		},

		draw: function() {
		
			var x = this.nodes[0].x, 
				y = this.nodes[0].y,
				a, b;
			
			ctx.beginPath();
			ctx.moveTo(x, y);
			
			for(var i = 1, n = this.nodes.length - 2; i < n; i++) {
				
				a = this.nodes[i];
				b = this.nodes[i + 1];
				x = (a.x + b.x) * 0.5;
				y = (a.y + b.y) * 0.5;
				
				ctx.quadraticCurveTo(a.x, a.y, x, y);
			}
			
			a = this.nodes[i];
			b = this.nodes[i + 1];
			
			ctx.quadraticCurveTo(a.x, a.y, b.x, b.y);
			ctx.stroke();
			ctx.closePath();
		}
	};

})();

// ----------------------------------------------------------------------------------------

function init(event) {

	document.removeEventListener('mousemove', init);
	document.removeEventListener('touchstart', init);
	
	document.addEventListener('mousemove', mousemove);
	document.addEventListener('touchmove', mousemove);
	document.addEventListener('touchstart', touchstart);
	
	mousemove(event);
	reset();
	loop();
}

function reset() {
	
	tendrils = [];

	for(var i = 0; i < settings.trails; i++) {
		
		tendrils.push(new Tendril({
			spring: 0.45 + 0.025 * (i / settings.trails)
		}));
	}
}

function loop() {
	
	if(!ctx.running) return;

	ctx.globalCompositeOperation = 'source-over';
	ctx.fillStyle = 'rgba(8,5,16,0.4)';
	ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
	ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
	ctx.globalCompositeOperation = 'lighter';
	ctx.strokeStyle = 'hsla(' + Math.round(hue.update()) + ',90%,50%,0.25)';
	ctx.lineWidth = 1;
	
	if(ctx.frame % 60 == 0) {
		console.log(hue.update(), Math.round(hue.update()), hue.phase, hue.offset, hue.frequency, hue.amplitude);
	}
	
	for(var i = 0, tendril; i < settings.trails; i++) {
		tendril = tendrils[i];
		tendril.update();
		tendril.draw();
	}
	
	ctx.frame++;
	//ctx.stats.update();
	requestAnimFrame(loop);
}

function resize() {
	ctx.canvas.width = window.innerWidth;
	ctx.canvas.height = window.innerHeight;
}

function start() {
	if(!ctx.running) {
		ctx.running = true;
		loop();
	}
}

function stop() {
	ctx.running = false;
}

function mousemove(event) {
	if(event.touches) {
		target.x = event.touches[0].pageX;
		target.y = event.touches[0].pageY;
	} else {
		target.x = event.clientX
		target.y = event.clientY;
	}
	event.preventDefault();
}

function touchstart(event) {
	if(event.touches.length == 1) {
		target.x = event.touches[0].pageX;
		target.y = event.touches[0].pageY;
	}
}

function keyup(event) {
	
	switch(event.keyCode) {
		case 32:
			//save();
			break;
		default: 
			// console.log(event.keyCode);
	}
}



function save() {

	if(!buffer) {
		
		buffer = document.createElement('canvas');
		buffer.width = screen.availWidth;
		buffer.height = screen.availHeight;
		buffer.ctx = buffer.getContext('2d');
		
		form = document.createElement('form');
		form.method = 'post';
		form.input = document.createElement('input');
		form.input.type = 'hidden';
		form.input.name = 'data';
		form.appendChild(form.input);
		
		document.body.appendChild(form);
	}

	buffer.ctx.fillStyle = 'rgba(8,5,16)';
	buffer.ctx.fillRect(0, 0, buffer.width, buffer.height);
	
	buffer.ctx.drawImage(canvas,
		Math.round(buffer.width / 2 - canvas.width / 2), 
		Math.round(buffer.height / 2 - canvas.height / 2)
	);
	
	buffer.ctx.drawImage(logo,
		Math.round(buffer.width / 2 - logo.width / 4), 
		Math.round(buffer.height / 2 - logo.height / 4),
		logo.width / 2,
		logo.height / 2
	);
	
	window.open(buffer.toDataURL(), 'wallpaper', 'top=0,left=0,width=' + buffer.width + ',height=' + buffer.height);
	
	// form.input.value = buffer.toDataURL().substr(22);
	// form.submit();
}

window.requestAnimFrame = (function() {
	return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function(fn) { window.setTimeout(fn, 1000 / 60) };
})();

window.onload = function() {
	
	ctx = document.getElementById('canvas').getContext('2d');
	//ctx.stats = new Stats();
	ctx.running = true;
	ctx.frame = 1;
	
	logo = new Image();
	//logo.src = 'http://labs.nikrowell.com/lightsandmotion/ultraviolet/images/logo.png';
	
	hue = new Oscillator({
		phase: Math.random() * Math.TWO_PI,
		amplitude: 85,
		frequency: 0.0015,
		offset: 285
	});
	
	//letters('h1');
	//letters('h2');
	
	document.addEventListener('mousemove', init);
	document.addEventListener('touchstart', init);
	document.body.addEventListener('orientationchange', resize);
	window.addEventListener('resize', resize);
	window.addEventListener('keyup', keyup);
	window.addEventListener('focus', start);
	window.addEventListener('blur', stop);
	
	resize();
	
	if(window.DEBUG) {
		
		var gui = new dat.GUI();
		
		// gui.add(settings, 'debug');
		settings.gui.add(settings, 'trails', 1, 30).onChange(reset);
		settings.gui.add(settings, 'size', 25, 75).onFinishChange(reset);
		settings.gui.add(settings, 'friction', 0.45, 0.55).onFinishChange(reset);
		settings.gui.add(settings, 'dampening', 0.01, 0.4).onFinishChange(reset);
		settings.gui.add(settings, 'tension', 0.95, 0.999).onFinishChange(reset);	
		
		//document.body.appendChild(ctx.stats.domElement);
	}
};

})(window);console.log("\u002f\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u000d\u000a\u0020\u002a\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u002a\u0009\u0009\u000d\u000a\u0020\u002a\u0020\u0009\u0009\u0009\u0009\u0009\u0009\u0020\u0020\u0020\u0020\u0020\u0020\u4ee3\u7801\u5e93\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u002a\u000d\u000a\u0020\u002a\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0077\u0077\u0077\u002e\u0064\u006d\u0061\u006b\u0075\u002e\u0063\u006f\u006d\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u002a\u000d\u000a\u0020\u002a\u0020\u0020\u0020\u0020\u0020\u0020\u0020\u0009\u0009\u0020\u0020\u52aa\u529b\u521b\u5efa\u5b8c\u5584\u3001\u6301\u7eed\u66f4\u65b0\u63d2\u4ef6\u4ee5\u53ca\u6a21\u677f\u0009\u0009\u0009\u002a\u000d\u000a\u0020\u002a\u0020\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u0009\u002a\u000d\u000a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002a\u002f");